Recent data suggest that Moderna’s coronavirus vaccine may over time be more effective than Pfizer.
Why it’s important: The efficacy gap could always disappear with more data and both vaccines remain very effective against serious diseases. But if the gap remains, questions arise as to whether the two vaccines should be treated the same according to policies.
Get market news worthy of your time with Axios Markets. Subscribe for free.
Leading the news: Several studies, both prepress and peer-reviewed, have found a difference between the effectiveness of the two vaccines over time, although some experts have warned that this could result from poor comparisons toward cap.
-
Studies have evaluated different measures of efficacy, but all have found that efficacy against serious diseases remains relatively high.
-
“There have been a kind of signs from fairly separate sources that are starting to paint a picture that might reflect a real biological phenomenon, a real difference. I’m beginning to believe there’s something underlying,” said Natalie Dean, Emery’s teacher. which specializes in the design of vaccine studies.
Zoom in: In a study published last week, the CDC found that Moderna was significantly more effective against hospitalizations and emergency service or urgent care meetings than Pfizer or J&J vaccines.
Between lines: Pfizer was the first vaccine authorized for the U.S. and began being administered several weeks before the Modern vaccine.
-
“Because of the way the launches took place, older, vulnerable and sick people, such as residents of residences, got Pfizer,” Cornell virologist John Moore said.
-
This means that part of the efficacy gap found in some studies may be the result of administering Pfizer earlier and in more vulnerable populations.
-
However, the large CDC study that found a significant difference in vaccine efficacy found that Moderna’s was higher at all ages.
Possible reasons for the difference include that Moderna has a much higher dosing regimen than Pfizer, and the second shot is given after a slightly longer interval.
Yes, but: Both vaccines are almost equal in their ability to “do what a vaccine has to do, which is protect against serious illness,” said Paul Offit, director of the Philadelphia Children’s Hospital’s Vaccine Education Center.
The summary: Moderna data may look more like Pfizer after spending more time. But it may be unwise to use one as a proxy for the other.
-
“It’s not clear that any lessons we see from Pfizer translate directly to Modern,” Dean said. “I think if you asked that question a few months ago, when there really is [weren’t] if there are signs of difference, people would bring them together a lot in their minds. “
What we are seeing: There is much more data, especially from other countries, such as Israel, on the declining effectiveness of Pfizer and the effect of booster shots on the recovery of effectiveness to the original levels.
-
But if this data isn’t applicable to Moderna, regulators may not yet have much data to work with when reinforcement decisions are made, a process that is already highly controversial.
-
“We won’t know Moderna’s specific actual data for a while, about restoring effectiveness and its durability,” said Eric Topol, executive vice president of Scripps Research.
-
Topol said there have been signs that Moderna’s effectiveness is declining over time to some extent. “It may be longer and less,” Topol added.
Do you like this article? Make the most of Axios and subscribe for free to Axios Markets.